The Ni/H reactor design allows for a huge amplification factor produced by many nanoparticles in chains.
An important problem in ’plasmonics’ is the question of how micro/nano particles should be designed and arranged with respect to each other to produce the strongest possible field enhancement. One possible solution to this problem is the configuration of a self-similar chain of particles with decreasing diameters [K. Li, M. I. Stockman, and D. J. Bergman.Self-similar chain of metal nanospheres as an efficient nanolens.Phys. Rev. Lett. 91, 227402 (2003). http://www.phy-astr.gsu.edu/stockman/data/PRL_91_27402_2003_Stockman_Nanolens.pdf] Self-similarity requires that radii Ri and the distances di,i+1 of the spheres i and i+1 are connected by the simple relations Ri+1 = ·Ri and di+1,i+2 = ·kdi,i+1 where · k<< 1. The last condition ensures that the field of a given nanoparticle is only a weak perturbation of the previous, bigger particle. The self-similarity is not a necessary condition but it allows for an elegant notation. All particles are considered in the electrostatic limit. Now, if each of the particles enhances its driving field by a certain factor (a), then the cumulative effect of the chain of particles is a field enhancement on the order of (a)n where n is the number of particles. In other words, the enhanced field of the largest particle acts as an excitation field for the next smaller particle. The resulting enhanced field of this second particle then acts as the excitation field for the next smaller particle, and so on. For the system depicted in Fig. 12.23 of Chapter 12 Surface plasmons http://www.optics.rochester.edu/workgroups/novotny/courses/OPT463/plasmonss.pdf assuming a moderate a » 10, leads to a total field enhancement of »1000 (every factor of 10 particles produces an enhancement of 1000 or 10 to the power of 3). As we will see in the following section, field enhancements of at least 1000 are necessary to observe the Raman scattering of single molecules adsorbed onto rough metal structures. Assume the largest particle is 7*10^^-6 (7 microns) and the smallest is a nanometer or 10^^-9 , then the size difference is 1.4 * 10^^4 There is a particle size amplification of about 10000. If there are 10,000 nanoparticles in the chain, there will be 1000 to the power of 3 particle enhancement factor or 1,000,000,000. That is a total enhancement factor of 10,000,000,000,000. Add the million volt nanowire enhancement in with the particle number/size enhancement and you get a big number.
